Adding upstream version 2.5.13+dfsg.upstream/2.5.13+dfsgupstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 739 insertions, 0 deletions

diff --git a/servers/slapd/sl_malloc.c b/servers/slapd/sl_malloc.c
new file mode 100644
index 0000000..9765bc3
--- /dev/null
+++ b/servers/slapd/sl_malloc.c
@@ -0,0 +1,739 @@
+/* sl_malloc.c - malloc routines using a per-thread slab */
+/* $OpenLDAP$ */
+/* This work is part of OpenLDAP Software <http://www.openldap.org/>.
+ *
+ * Copyright 2003-2022 The OpenLDAP Foundation.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted only as authorized by the OpenLDAP
+ * Public License.
+ *
+ * A copy of this license is available in the file LICENSE in the
+ * top-level directory of the distribution or, alternatively, at
+ * <http://www.OpenLDAP.org/license.html>.
+ */
+
+#include "portable.h"
+
+#include <stdio.h>
+#include <ac/string.h>
+
+#include "slap.h"
+
+#ifdef USE_VALGRIND
+/* Get debugging help from Valgrind */
+#include <valgrind/memcheck.h>
+#define	VGMEMP_MARK(m,s)	VALGRIND_MAKE_MEM_NOACCESS(m,s)
+#define VGMEMP_CREATE(h,r,z)	VALGRIND_CREATE_MEMPOOL(h,r,z)
+#define VGMEMP_TRIM(h,a,s)	VALGRIND_MEMPOOL_TRIM(h,a,s)
+#define VGMEMP_ALLOC(h,a,s)	VALGRIND_MEMPOOL_ALLOC(h,a,s)
+#define VGMEMP_CHANGE(h,a,b,s)	VALGRIND_MEMPOOL_CHANGE(h,a,b,s)
+#else
+#define	VGMEMP_MARK(m,s)
+#define VGMEMP_CREATE(h,r,z)
+#define VGMEMP_TRIM(h,a,s)
+#define VGMEMP_ALLOC(h,a,s)
+#define VGMEMP_CHANGE(h,a,b,s)
+#endif
+
+/*
+ * This allocator returns temporary memory from a slab in a given memory
+ * context, aligned on a 2-int boundary.  It cannot be used for data
+ * which will outlive the task allocating it.
+ *
+ * A new memory context attaches to the creator's thread context, if any.
+ * Threads cannot use other threads' memory contexts; there are no locks.
+ *
+ * The caller of slap_sl_malloc, usually a thread pool task, must
+ * slap_sl_free the memory before finishing: New tasks reuse the context
+ * and normally reset it, reclaiming memory left over from last task.
+ *
+ * The allocator helps memory fragmentation, speed and memory leaks.
+ * It is not (yet) reliable as a garbage collector:
+ *
+ * It falls back to context NULL - plain ber_memalloc() - when the
+ * context's slab is full.  A reset does not reclaim such memory.
+ * Conversely, free/realloc of data not from the given context assumes
+ * context NULL.  The data must not belong to another memory context.
+ *
+ * Code which has lost track of the current memory context can try
+ * slap_sl_context() or ch_malloc.c:ch_free/ch_realloc().
+ *
+ * Allocations cannot yet return failure.  Like ch_malloc, they succeed
+ * or abort slapd.  This will change, do fix code which assumes success.
+ */
+
+/*
+ * The stack-based allocator stores (ber_len_t)sizeof(head+block) at
+ * allocated blocks' head - and in freed blocks also at the tail, marked
+ * by ORing *next* block's head with 1.  Freed blocks are only reclaimed
+ * from the last block forward.  This is fast, but when a block is never
+ * freed, older blocks will not be reclaimed until the slab is reset...
+ */
+
+#ifdef SLAP_NO_SL_MALLOC /* Useful with memory debuggers like Valgrind */
+enum { No_sl_malloc = 1 };
+#else
+enum { No_sl_malloc = 0 };
+#endif
+
+#define SLAP_SLAB_SOBLOCK 64
+
+struct slab_object {
+    void *so_ptr;
+	int so_blockhead;
+    LDAP_LIST_ENTRY(slab_object) so_link;
+};
+
+struct slab_heap {
+    void *sh_base;
+    void *sh_last;
+    void *sh_end;
+	int sh_stack;
+	int sh_maxorder;
+    unsigned char **sh_map;
+    LDAP_LIST_HEAD(sh_freelist, slab_object) *sh_free;
+	LDAP_LIST_HEAD(sh_so, slab_object) sh_sopool;
+};
+
+enum {
+	Align = sizeof(ber_len_t) > 2*sizeof(int)
+		? sizeof(ber_len_t) : 2*sizeof(int),
+	Align_log2 = 1 + (Align>2) + (Align>4) + (Align>8) + (Align>16),
+	order_start = Align_log2 - 1,
+	pad = Align - 1
+};
+
+static struct slab_object * slap_replenish_sopool(struct slab_heap* sh);
+#ifdef SLAPD_UNUSED
+static void print_slheap(int level, void *ctx);
+#endif
+
+/* Keep memory context in a thread-local var */
+# define memctx_key ((void *) slap_sl_mem_init)
+# define SET_MEMCTX(thrctx, memctx, kfree) \
+	ldap_pvt_thread_pool_setkey(thrctx,memctx_key, memctx,kfree, NULL,NULL)
+# define GET_MEMCTX(thrctx, memctxp) \
+	((void) (*(memctxp) = NULL), \
+	 (void) ldap_pvt_thread_pool_getkey(thrctx,memctx_key, memctxp,NULL), \
+	 *(memctxp))
+
+/* Destroy the context, or if key==NULL clean it up for reuse. */
+void
+slap_sl_mem_destroy(
+	void *key,
+	void *data
+)
+{
+	struct slab_heap *sh = data;
+	struct slab_object *so;
+	int i;
+
+	if (!sh)
+		return;
+
+	if (!sh->sh_stack) {
+		for (i = 0; i <= sh->sh_maxorder - order_start; i++) {
+			so = LDAP_LIST_FIRST(&sh->sh_free[i]);
+			while (so) {
+				struct slab_object *so_tmp = so;
+				so = LDAP_LIST_NEXT(so, so_link);
+				LDAP_LIST_INSERT_HEAD(&sh->sh_sopool, so_tmp, so_link);
+			}
+			ch_free(sh->sh_map[i]);
+		}
+		ch_free(sh->sh_free);
+		ch_free(sh->sh_map);
+
+		so = LDAP_LIST_FIRST(&sh->sh_sopool);
+		while (so) {
+			struct slab_object *so_tmp = so;
+			so = LDAP_LIST_NEXT(so, so_link);
+			if (!so_tmp->so_blockhead) {
+				LDAP_LIST_REMOVE(so_tmp, so_link);
+			}
+		}
+		so = LDAP_LIST_FIRST(&sh->sh_sopool);
+		while (so) {
+			struct slab_object *so_tmp = so;
+			so = LDAP_LIST_NEXT(so, so_link);
+			ch_free(so_tmp);
+		}
+	}
+
+	if (key != NULL) {
+		ber_memfree_x(sh->sh_base, NULL);
+		ber_memfree_x(sh, NULL);
+	}
+}
+
+BerMemoryFunctions slap_sl_mfuncs =
+	{ slap_sl_malloc, slap_sl_calloc, slap_sl_realloc, slap_sl_free };
+
+void
+slap_sl_mem_init()
+{
+	assert( Align == 1 << Align_log2 );
+
+	ber_set_option( NULL, LBER_OPT_MEMORY_FNS, &slap_sl_mfuncs );
+}
+
+/* Create, reset or just return the memory context of the current thread. */
+void *
+slap_sl_mem_create(
+	ber_len_t size,
+	int stack,
+	void *thrctx,
+	int new
+)
+{
+	void *memctx;
+	struct slab_heap *sh;
+	ber_len_t size_shift;
+	struct slab_object *so;
+	char *base, *newptr;
+	enum { Base_offset = (unsigned) -sizeof(ber_len_t) % Align };
+
+	sh = GET_MEMCTX(thrctx, &memctx);
+	if ( sh && !new )
+		return sh;
+
+	/* Round up to doubleword boundary, then make room for initial
+	 * padding, preserving expected available size for pool version */
+	size = ((size + Align-1) & -Align) + Base_offset;
+
+	if (!sh) {
+		sh = ch_malloc(sizeof(struct slab_heap));
+		base = ch_malloc(size);
+		SET_MEMCTX(thrctx, sh, slap_sl_mem_destroy);
+		VGMEMP_MARK(base, size);
+		VGMEMP_CREATE(sh, 0, 0);
+	} else {
+		slap_sl_mem_destroy(NULL, sh);
+		base = sh->sh_base;
+		if (size > (ber_len_t) ((char *) sh->sh_end - base)) {
+			newptr = ch_realloc(base, size);
+			if ( newptr == NULL ) return NULL;
+			VGMEMP_CHANGE(sh, base, newptr, size);
+			base = newptr;
+		}
+		VGMEMP_TRIM(sh, base, 0);
+	}
+	sh->sh_base = base;
+	sh->sh_end = base + size;
+
+	/* Align (base + head of first block) == first returned block */
+	base += Base_offset;
+	size -= Base_offset;
+
+	sh->sh_stack = stack;
+	if (stack) {
+		sh->sh_last = base;
+
+	} else {
+		int i, order = -1, order_end = -1;
+
+		size_shift = size - 1;
+		do {
+			order_end++;
+		} while (size_shift >>= 1);
+		order = order_end - order_start + 1;
+		sh->sh_maxorder = order_end;
+
+		sh->sh_free = (struct sh_freelist *)
+						ch_malloc(order * sizeof(struct sh_freelist));
+		for (i = 0; i < order; i++) {
+			LDAP_LIST_INIT(&sh->sh_free[i]);
+		}
+
+		LDAP_LIST_INIT(&sh->sh_sopool);
+
+		if (LDAP_LIST_EMPTY(&sh->sh_sopool)) {
+			slap_replenish_sopool(sh);
+		}
+		so = LDAP_LIST_FIRST(&sh->sh_sopool);
+		LDAP_LIST_REMOVE(so, so_link);
+		so->so_ptr = base;
+
+		LDAP_LIST_INSERT_HEAD(&sh->sh_free[order-1], so, so_link);
+
+		sh->sh_map = (unsigned char **)
+					ch_malloc(order * sizeof(unsigned char *));
+		for (i = 0; i < order; i++) {
+			int shiftamt = order_start + 1 + i;
+			int nummaps = size >> shiftamt;
+			assert(nummaps);
+			nummaps >>= 3;
+			if (!nummaps) nummaps = 1;
+			sh->sh_map[i] = (unsigned char *) ch_malloc(nummaps);
+			memset(sh->sh_map[i], 0, nummaps);
+		}
+	}
+
+	return sh;
+}
+
+/*
+ * Assign memory context to thread context. Use NULL to detach
+ * current memory context from thread. Future users must
+ * know the context, since ch_free/slap_sl_context() cannot find it.
+ */
+void
+slap_sl_mem_setctx(
+	void *thrctx,
+	void *memctx
+)
+{
+	SET_MEMCTX(thrctx, memctx, slap_sl_mem_destroy);
+}
+
+void *
+slap_sl_malloc(
+    ber_len_t	size,
+    void *ctx
+)
+{
+	struct slab_heap *sh = ctx;
+	ber_len_t *ptr, *newptr;
+
+	/* ber_set_option calls us like this */
+	if (No_sl_malloc || !ctx) {
+		newptr = ber_memalloc_x( size, NULL );
+		if ( newptr ) return newptr;
+		Debug(LDAP_DEBUG_ANY, "slap_sl_malloc of %lu bytes failed\n",
+			(unsigned long) size );
+		assert( 0 );
+		exit( EXIT_FAILURE );
+	}
+
+	/* Add room for head, ensure room for tail when freed, and
+	 * round up to doubleword boundary. */
+	size = (size + sizeof(ber_len_t) + Align-1 + !size) & -Align;
+
+	if (sh->sh_stack) {
+		if (size < (ber_len_t) ((char *) sh->sh_end - (char *) sh->sh_last)) {
+			newptr = sh->sh_last;
+			sh->sh_last = (char *) sh->sh_last + size;
+			VGMEMP_ALLOC(sh, newptr, size);
+			*newptr++ = size;
+			return( (void *)newptr );
+		}
+
+		size -= sizeof(ber_len_t);
+
+	} else {
+		struct slab_object *so_new, *so_left, *so_right;
+		ber_len_t size_shift;
+		unsigned long diff;
+		int i, j, order = -1;
+
+		size_shift = size - 1;
+		do {
+			order++;
+		} while (size_shift >>= 1);
+
+		size -= sizeof(ber_len_t);
+
+		for (i = order; i <= sh->sh_maxorder &&
+				LDAP_LIST_EMPTY(&sh->sh_free[i-order_start]); i++);
+
+		if (i == order) {
+			so_new = LDAP_LIST_FIRST(&sh->sh_free[i-order_start]);
+			LDAP_LIST_REMOVE(so_new, so_link);
+			ptr = so_new->so_ptr;
+			diff = (unsigned long)((char*)ptr -
+					(char*)sh->sh_base) >> (order + 1);
+			sh->sh_map[order-order_start][diff>>3] |= (1 << (diff & 0x7));
+			*ptr++ = size;
+			LDAP_LIST_INSERT_HEAD(&sh->sh_sopool, so_new, so_link);
+			return((void*)ptr);
+		} else if (i <= sh->sh_maxorder) {
+			for (j = i; j > order; j--) {
+				so_left = LDAP_LIST_FIRST(&sh->sh_free[j-order_start]);
+				LDAP_LIST_REMOVE(so_left, so_link);
+				if (LDAP_LIST_EMPTY(&sh->sh_sopool)) {
+					slap_replenish_sopool(sh);
+				}
+				so_right = LDAP_LIST_FIRST(&sh->sh_sopool);
+				LDAP_LIST_REMOVE(so_right, so_link);
+				so_right->so_ptr = (void *)((char *)so_left->so_ptr + (1 << j));
+				if (j == order + 1) {
+					ptr = so_left->so_ptr;
+					diff = (unsigned long)((char*)ptr -
+							(char*)sh->sh_base) >> (order+1);
+					sh->sh_map[order-order_start][diff>>3] |=
+							(1 << (diff & 0x7));
+					*ptr++ = size;
+					LDAP_LIST_INSERT_HEAD(
+							&sh->sh_free[j-1-order_start], so_right, so_link);
+					LDAP_LIST_INSERT_HEAD(&sh->sh_sopool, so_left, so_link);
+					return((void*)ptr);
+				} else {
+					LDAP_LIST_INSERT_HEAD(
+							&sh->sh_free[j-1-order_start], so_right, so_link);
+					LDAP_LIST_INSERT_HEAD(
+							&sh->sh_free[j-1-order_start], so_left, so_link);
+				}
+			}
+		}
+		/* FIXME: missing return; guessing we failed... */
+	}
+
+	Debug(LDAP_DEBUG_TRACE,
+		"sl_malloc %lu: ch_malloc\n",
+		(unsigned long) size );
+	return ch_malloc(size);
+}
+
+#define LIM_SQRT(t) /* some value < sqrt(max value of unsigned type t) */ \
+	((0UL|(t)-1) >>31>>31 > 1 ? ((t)1 <<32) - 1 : \
+	 (0UL|(t)-1) >>31 ? 65535U : (0UL|(t)-1) >>15 ? 255U : 15U)
+
+void *
+slap_sl_calloc( ber_len_t n, ber_len_t size, void *ctx )
+{
+	void *newptr;
+	ber_len_t total = n * size;
+
+	/* The sqrt test is a slight optimization: often avoids the division */
+	if ((n | size) <= LIM_SQRT(ber_len_t) || n == 0 || total/n == size) {
+		newptr = slap_sl_malloc( total, ctx );
+		memset( newptr, 0, n*size );
+	} else {
+		Debug(LDAP_DEBUG_ANY, "slap_sl_calloc(%lu,%lu) out of range\n",
+			(unsigned long) n, (unsigned long) size );
+		assert(0);
+		exit(EXIT_FAILURE);
+	}
+	return newptr;
+}
+
+void *
+slap_sl_realloc(void *ptr, ber_len_t size, void *ctx)
+{
+	struct slab_heap *sh = ctx;
+	ber_len_t oldsize, *p = (ber_len_t *) ptr, *nextp;
+	void *newptr;
+
+	if (ptr == NULL)
+		return slap_sl_malloc(size, ctx);
+
+	/* Not our memory? */
+	if (No_sl_malloc || !sh || ptr < sh->sh_base || ptr >= sh->sh_end) {
+		/* Like ch_realloc(), except not trying a new context */
+		newptr = ber_memrealloc_x(ptr, size, NULL);
+		if (newptr) {
+			return newptr;
+		}
+		Debug(LDAP_DEBUG_ANY, "slap_sl_realloc of %lu bytes failed\n",
+			(unsigned long) size );
+		assert(0);
+		exit( EXIT_FAILURE );
+	}
+
+	if (size == 0) {
+		slap_sl_free(ptr, ctx);
+		return NULL;
+	}
+
+	oldsize = p[-1];
+
+	if (sh->sh_stack) {
+		/* Add room for head, round up to doubleword boundary */
+		size = (size + sizeof(ber_len_t) + Align-1) & -Align;
+
+		p--;
+
+		/* Never shrink blocks */
+		if (size <= oldsize) {
+			return ptr;
+		}
+	
+		oldsize &= -2;
+		nextp = (ber_len_t *) ((char *) p + oldsize);
+
+		/* If reallocing the last block, try to grow it */
+		if (nextp == sh->sh_last) {
+			if (size < (ber_len_t) ((char *) sh->sh_end - (char *) p)) {
+				sh->sh_last = (char *) p + size;
+				p[0] = (p[0] & 1) | size;
+				return ptr;
+			}
+
+		/* Nowhere to grow, need to alloc and copy */
+		} else {
+			/* Slight optimization of the final realloc variant */
+			newptr = slap_sl_malloc(size-sizeof(ber_len_t), ctx);
+			AC_MEMCPY(newptr, ptr, oldsize-sizeof(ber_len_t));
+			/* Not last block, can just mark old region as free */
+			nextp[-1] = oldsize;
+			nextp[0] |= 1;
+			return newptr;
+		}
+
+		size -= sizeof(ber_len_t);
+		oldsize -= sizeof(ber_len_t);
+
+	} else if (oldsize > size) {
+		oldsize = size;
+	}
+
+	newptr = slap_sl_malloc(size, ctx);
+	AC_MEMCPY(newptr, ptr, oldsize);
+	slap_sl_free(ptr, ctx);
+	return newptr;
+}
+
+void
+slap_sl_free(void *ptr, void *ctx)
+{
+	struct slab_heap *sh = ctx;
+	ber_len_t size;
+	ber_len_t *p = ptr, *nextp, *tmpp;
+
+	if (!ptr)
+		return;
+
+	if (No_sl_malloc || !sh || ptr < sh->sh_base || ptr >= sh->sh_end) {
+		ber_memfree_x(ptr, NULL);
+		return;
+	}
+
+	size = *(--p);
+
+	if (sh->sh_stack) {
+		size &= -2;
+		nextp = (ber_len_t *) ((char *) p + size);
+		if (sh->sh_last != nextp) {
+			/* Mark it free: tail = size, head of next block |= 1 */
+			nextp[-1] = size;
+			nextp[0] |= 1;
+			/* We can't tell Valgrind about it yet, because we
+			 * still need read/write access to this block for
+			 * when we eventually get to reclaim it.
+			 */
+		} else {
+			/* Reclaim freed block(s) off tail */
+			while (*p & 1) {
+				p = (ber_len_t *) ((char *) p - p[-1]);
+			}
+			sh->sh_last = p;
+			VGMEMP_TRIM(sh, sh->sh_base,
+				(char *) sh->sh_last - (char *) sh->sh_base);
+		}
+
+	} else {
+		int size_shift, order_size;
+		struct slab_object *so;
+		unsigned long diff;
+		int i, inserted = 0, order = -1;
+
+		size_shift = size + sizeof(ber_len_t) - 1;
+		do {
+			order++;
+		} while (size_shift >>= 1);
+
+		for (i = order, tmpp = p; i <= sh->sh_maxorder; i++) {
+			order_size = 1 << (i+1);
+			diff = (unsigned long)((char*)tmpp - (char*)sh->sh_base) >> (i+1);
+			sh->sh_map[i-order_start][diff>>3] &= (~(1 << (diff & 0x7)));
+			if (diff == ((diff>>1)<<1)) {
+				if (!(sh->sh_map[i-order_start][(diff+1)>>3] &
+						(1<<((diff+1)&0x7)))) {
+					so = LDAP_LIST_FIRST(&sh->sh_free[i-order_start]);
+					while (so) {
+						if ((char*)so->so_ptr == (char*)tmpp) {
+							LDAP_LIST_REMOVE( so, so_link );
+						} else if ((char*)so->so_ptr ==
+								(char*)tmpp + order_size) {
+							LDAP_LIST_REMOVE(so, so_link);
+							break;
+						}
+						so = LDAP_LIST_NEXT(so, so_link);
+					}
+					if (so) {
+						if (i < sh->sh_maxorder) {
+							inserted = 1;
+							so->so_ptr = tmpp;
+							LDAP_LIST_INSERT_HEAD(&sh->sh_free[i-order_start+1],
+									so, so_link);
+						}
+						continue;
+					} else {
+						if (LDAP_LIST_EMPTY(&sh->sh_sopool)) {
+							slap_replenish_sopool(sh);
+						}
+						so = LDAP_LIST_FIRST(&sh->sh_sopool);
+						LDAP_LIST_REMOVE(so, so_link);
+						so->so_ptr = tmpp;
+						LDAP_LIST_INSERT_HEAD(&sh->sh_free[i-order_start],
+								so, so_link);
+						break;
+
+						Debug(LDAP_DEBUG_TRACE, "slap_sl_free: "
+							"free object not found while bit is clear.\n" );
+						assert(so != NULL);
+
+					}
+				} else {
+					if (!inserted) {
+						if (LDAP_LIST_EMPTY(&sh->sh_sopool)) {
+							slap_replenish_sopool(sh);
+						}
+						so = LDAP_LIST_FIRST(&sh->sh_sopool);
+						LDAP_LIST_REMOVE(so, so_link);
+						so->so_ptr = tmpp;
+						LDAP_LIST_INSERT_HEAD(&sh->sh_free[i-order_start],
+								so, so_link);
+					}
+					break;
+				}
+			} else {
+				if (!(sh->sh_map[i-order_start][(diff-1)>>3] &
+						(1<<((diff-1)&0x7)))) {
+					so = LDAP_LIST_FIRST(&sh->sh_free[i-order_start]);
+					while (so) {
+						if ((char*)so->so_ptr == (char*)tmpp) {
+							LDAP_LIST_REMOVE(so, so_link);
+						} else if ((char*)tmpp == (char *)so->so_ptr + order_size) {
+							LDAP_LIST_REMOVE(so, so_link);
+							tmpp = so->so_ptr;
+							break;
+						}
+						so = LDAP_LIST_NEXT(so, so_link);
+					}
+					if (so) {
+						if (i < sh->sh_maxorder) {
+							inserted = 1;
+							LDAP_LIST_INSERT_HEAD(&sh->sh_free[i-order_start+1],									so, so_link);
+							continue;
+						}
+					} else {
+						if (LDAP_LIST_EMPTY(&sh->sh_sopool)) {
+							slap_replenish_sopool(sh);
+						}
+						so = LDAP_LIST_FIRST(&sh->sh_sopool);
+						LDAP_LIST_REMOVE(so, so_link);
+						so->so_ptr = tmpp;
+						LDAP_LIST_INSERT_HEAD(&sh->sh_free[i-order_start],
+								so, so_link);
+						break;
+
+						Debug(LDAP_DEBUG_TRACE, "slap_sl_free: "
+							"free object not found while bit is clear.\n" );
+						assert(so != NULL);
+
+					}
+				} else {
+					if ( !inserted ) {
+						if (LDAP_LIST_EMPTY(&sh->sh_sopool)) {
+							slap_replenish_sopool(sh);
+						}
+						so = LDAP_LIST_FIRST(&sh->sh_sopool);
+						LDAP_LIST_REMOVE(so, so_link);
+						so->so_ptr = tmpp;
+						LDAP_LIST_INSERT_HEAD(&sh->sh_free[i-order_start],
+								so, so_link);
+					}
+					break;
+				}
+			}
+		}
+	}
+}
+
+void
+slap_sl_release( void *ptr, void *ctx )
+{
+	struct slab_heap *sh = ctx;
+	if ( sh && ptr >= sh->sh_base && ptr <= sh->sh_end )
+		sh->sh_last = ptr;
+}
+
+void *
+slap_sl_mark( void *ctx )
+{
+	struct slab_heap *sh = ctx;
+	return sh->sh_last;
+}
+
+/*
+ * Return the memory context of the current thread if the given block of
+ * memory belongs to it, otherwise return NULL.
+ */
+void *
+slap_sl_context( void *ptr )
+{
+	void *memctx;
+	struct slab_heap *sh;
+
+	if ( slapMode & SLAP_TOOL_MODE ) return NULL;
+
+	sh = GET_MEMCTX(ldap_pvt_thread_pool_context(), &memctx);
+	if (sh && ptr >= sh->sh_base && ptr <= sh->sh_end) {
+		return sh;
+	}
+	return NULL;
+}
+
+static struct slab_object *
+slap_replenish_sopool(
+    struct slab_heap* sh
+)
+{
+    struct slab_object *so_block;
+    int i;
+
+    so_block = (struct slab_object *)ch_malloc(
+                    SLAP_SLAB_SOBLOCK * sizeof(struct slab_object));
+
+    if ( so_block == NULL ) {
+        return NULL;
+    }
+
+    so_block[0].so_blockhead = 1;
+    LDAP_LIST_INSERT_HEAD(&sh->sh_sopool, &so_block[0], so_link);
+    for (i = 1; i < SLAP_SLAB_SOBLOCK; i++) {
+        so_block[i].so_blockhead = 0;
+        LDAP_LIST_INSERT_HEAD(&sh->sh_sopool, &so_block[i], so_link );
+    }
+
+    return so_block;
+}
+
+#ifdef SLAPD_UNUSED
+static void
+print_slheap(int level, void *ctx)
+{
+	struct slab_heap *sh = ctx;
+	struct slab_object *so;
+	int i, j, once = 0;
+
+	if (!ctx) {
+		Debug(level, "NULL memctx\n" );
+		return;
+	}
+
+	Debug(level, "sh->sh_maxorder=%d\n", sh->sh_maxorder );
+
+	for (i = order_start; i <= sh->sh_maxorder; i++) {
+		once = 0;
+		Debug(level, "order=%d\n", i );
+		for (j = 0; j < (1<<(sh->sh_maxorder-i))/8; j++) {
+			Debug(level, "%02x ", sh->sh_map[i-order_start][j] );
+			once = 1;
+		}
+		if (!once) {
+			Debug(level, "%02x ", sh->sh_map[i-order_start][0] );
+		}
+		Debug(level, "\n" );
+		Debug(level, "free list:\n" );
+		so = LDAP_LIST_FIRST(&sh->sh_free[i-order_start]);
+		while (so) {
+			Debug(level, "%p\n", so->so_ptr );
+			so = LDAP_LIST_NEXT(so, so_link);
+		}
+	}
+}
+#endif